Former South Korean President Yoon Suk Yeol is back in custody over an independent investigation into his declaration of martial law last year.

A South Korean court early Thursday approved the new arrest of former president Yoon Suk Yeol on charges related to his brief imposition of martial law in December.

Yoon, who was the first sitting South Korean president to be arrested, faces trial on charges of leading an insurrection over his attempt to impose martial law. During Wednesday's seven-hour hearing, a special counsel team argued for the arrest warrant on five key charges, South Korean news agency Yonhap reported.